clear all;close all

A = xlsread('LfieldvsQb.xlsx');

figure
h=semilogx(A(:,1),A(:,2),'b');set(h,'linewidth',2);hold on
h=semilogx(A(:,1),A(:,3),'r');set(h,'linewidth',2);
h=semilogx(A(:,1),A(:,4),'g');set(h,'linewidth',2);

set(gca,'fontsize',20)
axis square
xlabel('|q_b| [nC]');ylabel('L_{field} [m]')
legend('V_r(t=0)=0','V_r(t=0)=1.2\cdot 10^7 m/s','q_b^{eff}=0','location','northoutside','orientation','horizonthal')
legend boxoff